Response to Biologic Drugs in Patients With Rheumatoid Arthritis and Antidrug Antibodies

Area of Science:

• Rheumatology
• Immunology
• Pharmacology

Background:

• Conflicting data exist regarding the association between antidrug antibodies and treatment response in rheumatoid arthritis (RA) patients receiving biologic disease-modifying antirheumatic drugs (bDMARDs).
• Understanding this association is crucial for optimizing bDMARD therapy in RA management.

Purpose of the Study:

• To investigate the association between antidrug antibodies and treatment response in patients with RA initiating bDMARD therapy.
• To identify factors influencing the efficacy of bDMARDs in RA.

Main Methods:

• A prospective, multicentric cohort study (ABI-RA) involving 230 RA patients from 4 European countries initiating a new bDMARD (adalimumab, infliximab, etanercept, tocilizumab, or rituximab).
• Antidrug antibody serum levels and drug concentrations were measured at multiple time points.
• European Alliance of Associations for Rheumatology (EULAR) response was assessed at 6 and 12 months using logistic regression and generalized estimating equation models.

Main Results:

• Antidrug antibody positivity was observed in 38.2% (anti-TNF mAbs), 6.1% (etanercept), 50.0% (rituximab), and 20.0% (tocilizumab) of patients at month 12.
• A significant inverse association was found between antidrug antibody positivity and EULAR response at 12 months (OR, 0.19; P < .001) and across all visits from month 6 (OR, 0.35; P < .001).
• Antidrug antibodies, body mass index, and rheumatoid factor were independently associated with nonresponse to treatment; methotrexate comedication was inversely associated with antidrug antibodies.

Conclusions:

• This study suggests a significant association between antidrug antibodies and nonresponse to bDMARDs in RA patients.
• Monitoring antidrug antibodies could be a valuable strategy in managing RA patients, particularly those not responding to biologic therapies.
• Further research may elucidate optimal monitoring and management strategies for antidrug antibodies in RA.